Gas mileage

[guitar guru]

I'm getting terrible gas mileage (20-30 mpg) for my '86 Suzuki 550 and it's not cause I rev high. Could the carbs be the problem. I think they were cleaned before I bought it, but I'm not 100% on that. Would leaving the choke on be a possible problem, 'cause if I don't leave the choke on for about ten minutes it'll stall when I stop. I'm not the most mechanically savvy biker and I'd like to get this taken care of, but don't know what to do.

[TechTMW]

Would leaving the choke on be a possible problem

Yes.

Most likely the idle circuit in your carbs is blocked, and they need a good professional cleaning. You can do it yourself but you relly have to work to get those tiny passages clean in the idle circuit, so it's usually easier to get it done professionally. (Ask anyone who's had to take their carbs off multiple times )

Your choke being on actually opens up what is basically a separate fuel and air circuit to make your mix rich for cold-starting. So by leaving the choke on, your mix remains rich (too much gas) after the bike warms up.